Down draft apparatus for cooling food products



H. D. LEIBOLD $833,124

DOWN DRAFT APPARATUS FOR COOLING FOOD PRODUCTS May 6, 1958 Filed Oct. 22. 1956 V 5 I B m H m 1 003181 rl 2 0/, M Q Q h a \W I! 3 M 2 14 4 w h I v 8 & W |I 3 \(V |)l r "I B AIBI' 3W M E ATTOENEYS United States Patent nowN DRAFT APPARATUS FOR COOLING noon PRODUCTS Harry D. Leibold, South Euclid, Ohio Application October 22, 1956, Serial No. 617,321

3 Claims. (Cl. 62-915) centrally thereof and providing suflicient refrigeration.

capacity .to maintain frozen food products contained on said table at an appropriate temperature to prevent spoilage.

Another object of the presentinvention is to provide a refrigerated display table which employs Dry Ice as a.

cooling agent whereinthe consumption of said cooling agent is reduced by approximately one-half as compared with presently known similar sized display cases.

Another object of the present invention is to provide a frozen food display case which uses Dry Ice as the refrigerant and employs a novel Dry Ice container which provides a guard that completely shields the Dry Ice and prevents contact therewith, while simultaneously reducing the consumption of the Dry Ice and maintaining proper temperature. v 6

Still another objectof the present invention is to providea novel refrigerated display case employing Dry Ice as a refrigerant which will readily serve as auxiliary refrigerating equipment to permit extra displays for frozen foods wherein the foods are displayed in a high-level, eyecatching manner to increase impulse purchases of said products.

3 Another object of the presentinvention is to provide a simple, portable Dry Ice container which need only be positioned in an appropriate tablev to make an efiicient arrangement for preserving and'displaying packages of frozen food. v 7

Another object of the present invention is to provide a down draft display case for cooling food products characterized by its structural simplicity, the ease of assembly of its parts, its strong and sturdy nature and its low manufacturing cost.

Other features of this invention reside in the arrangement and design of the parts for carrying out their appropriate functions. I

Further objects of the present invention and certain practical advantages will be referred to in or will be evident from the following description of one embodiment of the invention as illustrated in the accompanying drawings, in which;

. Fig. 1 is a perspective view showing the display table or case'with a plurality of frozen food packages scattered at random therein and having my improved Dry Ice container positioned centrally thereof.

Fig. 2 is an enlarged fragmentary cross-sectional view taken through the center of the Dry Ice container and table of Fig. 1, showing the dimensions of the Dry Ice inches by ten inches.

'2 guard and container relative to its associated supporting case or table.

Fig. 3 is a transverse, horizontal, sectional view taken along the plane of line 33 of Fig. 2, showing the relative size of the block of Dry Ice and its associated container.

Before describing in detail the herein disclosed embodiment of the invention, it is to be understood that the present invention is not limited to the structural details or the particular arrangement of parts herein shown, as.

devices embodying the present invention may takeother forms.

It also is to be understood that the phraseology and terminology herein used are for purposes of description and not of limitation, as the scope of the present invention is denoted by the appended claims.

Referring now to Fig. 1, wherein I have shown a perspective view of my improved device which includes in general a display table or case 10 and means for cooling said display case. In-the present invention, the display case takes the form of a fiat-top table 11 havingsupporting legs 12 and provided with upright skirts or sidewalls 13 which completely surround and enclose the outer periphery of the table 11. In the preferred construction of the present invention, the table is approximately four feet square and the upright sidewalls or skirt boards 11 are approximately six inches high. A produce table is ideal for this purpose and the upright sidewalls may be improvised from cardboard, lumber, or any other suitable means. Whatever the means employed, it is important to maintain a good seal between the upright skirts 13 and the table 11, so as to prevent loss of cold through leakage. The height of the table 11 should be such that the products contained thereon are'maintained at an eyecatching level, and a level at which the products may be readily removed by a person of average size without undue bending or stretching.

The open-top display case provided by table 11 is provided with suitable refrigerating means in heat-exchanging relation therewith. The refrigerating means employs as a refrigerant a block of Dry Ice 14 contained in a novel Dry Ice container 15, positioned substantially in the center of table 11. The Dry Ice container 15 in the preferred construction is a substantially square box having four upright sidewalls 16 and a flat bottom 17. A

removable top 18, as seen in Fig. 2, is provided for the container. Top 18 has depending lips 18a which extend completely around its outer periphery. The depending lips 18a frictionally engage in close contact the upright sidewalls 16 of the container 15, as clearly seen in Fig. 2.

The container 15 is supported above the level of table 11 by means of four legs 19 which are formed in any suitable manner, here shown as angle irons rigidly secured to the container 15. The preferred dimension of the container 15 is 11" by 11" by 11", this being a size which will readily accommodate a fifty-pound cube of Dry Ice 14 which is approximately ten inches by ten The cube of solid carbon dioxide or Dry Ice 14 rests on the bottom 17 of the container and due to its smaller dimensions it is located in spaced relation to the four sidewalls 16 of the container 15. In the position, as seen in Figs. 2 and 3, the cube of Dry Ice 14 provides passages 21, 22, 23 and 24 between its own outer surface and the inner surfaces of sidewalls 16 of the container 15. The passages 21, 22, 23 and 24 are each about one-half inch wide with a fresh cube of Dry Ice and this gives good heat exchange between a downwardly moving stream of air and the cube of Dry Ice. It should be noted also that the top of the Dry Ice cube 14 is maintained a slight distance spaced below the top 18 of the container as best seen in Fig. 2. This is about one inch with the preferred l0" cube and enhances intimate contact between the air and the Dry Ice.

Means are provided for permitting a' controlled circula tion of air downwardly through the top 18 of the container 15, through the passages 21, 22, 23 and 24 between the cube of Dry Ice and the walls of the container and outwardly through the bottom 17 of the container. Said control means here takes the form of spaced slots 1812 provided in the top 18. The metal of top 18 along the outer edge of the slots is turned upwardly to form louvers 26 which promote the intake of air for circulation within the container 15. By limiting the number and size of slots 18b, the flow of air is controlled. The bottom of the container is provided with a plurality of perforations 17a, as seen in Fig. 2, to permit egress of the cooled air from within the container 15. Here the area of the openings 18b in the top of the container 15 is less than the area of the perforations 17a in the bottom of the container so that the top openings control the flow. The container may also be constructed in a manner wherein the area of the perforations 17a in the bottom of the container is less than the area of the holes in the top of the container so that the number and size of openings 17a give air stream flow control. In either case the flow of air through the container is controlled. The area of the passages 21, 22, 23 and 24 is preferably greater'than the total area of louvers 26 or perforations 17a.

Thus, in operation it is seen that the cube of Dry Ice 1 divides the interior of the container 15 into a plurality of passages in such a manner that all incoming air through louvers 26 of the container must flow across the surface of the cube of Dry Ice anddownwardly as indicated by arrows 28 of Fig. 2 between the passages provided be tween the outer surface of the cube of Dry Ice and the inner surface of the sidewalls of the container and outwardly through the perforations 17a contained in the bottom of the container. Even as the cube of Dry Ice evaporates, it always compels the air to flow aroundit before. passing out through perforations 17a. The air during the process of flowing across the surface of the cube of Dry Ice becomes cooled thereby, the degree of coldness being determined by the velocity of the air as it flows across the surface of the cube of Dry Ice. The airflow velocity is controlled by louvers and perforations 18b and 17a respectively provided in container 15. It will be noted in Fig. 2 that the bottom of the container 15 is maintained preferably on a level with the upper edge of the upstanding skirts 13. The distance be tween the table top 11 and the bottom 17 of container 15 is designated by the letter A in Fig. 2. The distance A is substantially equal to the height of the upstanding skirts 13 which is designated by the letter B. Thus, the discharge perforations 17a contained in the bottom of the container 15 are located at a point above the normal level" of the articles 3-0 contained in the display space provided by the table 11 and its enclosing sidewalls 13, while still remaining within the confines of the upstanding skirts13 due to the dimension A"approximately equaling that of BZas heretofore described. Cold air coming out of perforations 17a must move slightly upwardly to escape over. skirts 13. This will onlyhappen as the cold air warms up.

The operation of the present device should now be apparent. Frozen food packages are placed within the display case at random or in a wel'l-jumbledmanncr was to leave a small gap or passage between adjacent packages to permit circulation of the cold air around each package. Since the normal flow of cold air is downward, the refrigerant (Dry Ice in this case) is placed above the merchandise in order to insure the proper cooling effect.

Warmair entering louvers 26 is cooled within the container 15by the cube of Dry Ice 14 and fiows downwardly and outwardly through the perforations 17a contained in the bottom of the container and into the opentop display case provided by the table 11 and its upstanding skirts 13; The container 15 serves not only to support the Dry Ice above the level of the food packages contained in the display case, but in addition thereto acts as a guard to keep customers and particularly children from burning their hands on the Dry Ice or from putting chips of the Dry Ice in their mouths. The upstanding skirts 13 as mentioned above provide the open-top encasement together with the table top 11 for displaying frozen food packages but in addition thereto also act as a retainer for the refrigerated air and keeps the cold air loss to a minimum. Each of the above factors contributes to reducing the consumption of Dry Ice to approximately one-half of the amount used in similar sized displays of other constructions known to me. Hence, the present device is much more economical in its operation than previous devices of this kind. The Dry Ice container 15 is so constructed as to be readily removed from the table top 11 and placed on another similar table, or stored when not in use.

It will be further noted that the outer side walls 16 of the container 15 are provided with suitable spring clips 31 which permit the easy securement of suitable signs relating to, and advertising the products contained in the refrigerated display case.

In view of the foregoing description taken in conjunction with the accompanying drawings, it 'is believed that a clear understanding of the construction, operation and advantages of the device will be quite apparent to those skilled in this art.

Having thus described my invention and illustrated its use, what I claim is new and desire to secure by Letters Patent is:

l. A refrigerating display case comprising a fiat open top table, said table being approximately four feet square and having upright skirts completely surrounding and enclosing the outer periphery of said table, said upright skirts being approximately six inches high, a removable Dry Ice container positioned substantially in the center of said table, said container being approximately eleven inches high by eleven inches long by eleven inches wide and adapted to accommodate a ten inch cube of Dry Ice, said cube of Dry Ice when resting in the bottom of said container and positioned centrally thereof dividing the interior of said container into a plurality of passages, said passages being provided between the outer surfaces of said cube of Dry Ice and the inner surfaces of the side Walls of said container, a removable top on said container,said top having a plurality of spaced slots provided therein, said slots being turned upwardly to form louvers which promote the intake of air through said top, said container provided witha bottom having a plurality of discharge perforations therein, the area of said passages provided between the outer'surfaces of said cube of Dry Ice and the side walls being greater than the area of said louvers provided in said top or said perforations provided in said bottom, means on said container supporting the bottom of said container at a level no higher than the upper edge of said upstanding skirts, whereby warm air entering said louvers is cooled within said container by said cube of Dry Ice' and passes downwardly and outwardly through said perforations contained in the bottom of said container into the open top display case and is retained therein by said upstanding skirts.

2. A refrigerator display case comprising a fiat open top table, said table having upright skirts completely surrounding and enclosing the outer periphery ofsaid table, a removable Dry Ice container positioned substantially in the center of said table, said container being adapted to accommodate a cube of Dry Ice, said cube of Dry Ice when resting in the bottom of said container and positioned centrally thereof dividing the interior of said container into a plurality of passages, said passages being provided between the outer surfaces of said cube of Dry Ice and the inner surfaces of the side walls of said container, a removable top on said container, said top having a plurality of spaced slots pro- 5. vided therein, said slots being turned upwardly to form louvers which promote the intake of air through said top, said container provided with a bottom having a plurality of discharge perforations therein, the area of said passages provided between the outer surface of said cube of Dry Ice and the side walls being greater than the area of said louvers provided in saidtop or said perforations provided in said bottom, means on said container supporting the bottom of said container at a level no higher than the upper edge of said upstanding skirts, whereby Warm air entering said louvers is cooled Within said container 'by said cube of Dry Ice and closed downwardly and outwardly through said perforations contained in the bottom of said container into the open top display case and is retained therein by said upstanding skirts.

3. A refrigerating display table comprising a fiat open top table, said table being approximately square and having upright skirts completely surrounding and enclosing the outer periphery of said table, said upright skirts having a height equal to approximately one-eighth of the length of said table, a removable Dry Ice container positioned substantially in the center of said table, said container being a cube having dimensions equal to approximately one-quarter of the length of said table and adapted to accommodate a cube of Dry Ice of smaller dimension than said container, said cube of Dry Ice when resting in the bottom of said container and positioned centrally thereof dividing the interior of said container into a plurality of passages, said passages being provided between the outer surface of said cub of Dry Ice and the inner surface of the side walls of said container, a top on said container, said top having a plurality of openings provided therein, which promote the intake of air through said top, said container provided with a bottom having a plurality of discharge perforations therein,wherehy warm air entering said openings in said top is cooled within said container by said cube of Dry Ice and passes downwardly and outwardly through said perforations contained in the bottom of said container into the open top display case and is retained therein by said upstanding skirts.

References Cited in the file of this patent UNITED STATES PATENTS 

